Often individuals having one or many joints or muscles which are over solicited suffer from repetition motion syndromes A method and a device using a specific mechanical stimulation (SMS) at an articulated body joint to facilitate or to inhibit the reflex response of the associated muscles, thus preventing these muscles from being over solicited or enabling them to relax is described in U.S. Pat. No. 5,769,810 granted to Brossard on Jun. 23, 1998.
The prior art teaches that the natural reflex mechanism of muscles associated with articulating joints such as the wrist, ankle and lumbar spine is guided by the respective mechano-receptors of these muscles. It was described that a light SMS pressure intensity (.ltorsim.200 mmHg) stimulates only skin mechano-receptors (such as the Pacinian corpuscles) of the wrist ankle and lumbar spine joints, hence facilitating the reflex response of the muscles associated with these joints, improving the efficiency thereof On the contrary, a high SMS pressure intensity (.gtorsim.400 mmHg) stimulates the above mentioned skin mechano-receptors and deeper joint mechano-receptors (such as Golgi tendons) of the wrist, ankle and lumbar spine joints to Inhibit the reflex response (reduction of the reflex response) of the respective muscles, thereby relaxing these muscles. Furthermore, it was observed that a medium pressure intensity (&gt;200 mmHg but &lt;400 mmHg) has substantially no effect. The information from the mechano-receptors is transmitted to many levels of the central nervous system. Mainly, the information from the mechano-receptors is transmitted to the spinal cord and brain. As the information is transmitted to the spinal cord, it influences the motor reflexes. Being transmitted to the brain it also influences central control of the joint movements.
U.S. Pat. No. 5,769,810 describes generally hemispherical pressure-applying protuberances for applyying either a low or high SMS pressure to specific external areas of the wrist, ankle and lumbar spine joints. These specific external areas correspond to the mechano-receptors, These pressure-applying members are mounted to support members adapted to be mounted to the wrist, ankle and lumbar spine joints.
The limitation with the prior art is that there are variations in distance between the body joint and the respective support member during certain articulating movements. These articulating movements further cause movements of the pressure-applying protuberance, causing variations in the SMS pressure intensity applied to the stimulated area(s). The disadvantages are that these variations sometimes fall within the middle pressure intensity (&gt;200 mmHg but &lt;400 mmHg) or that the protuberance Is no longer engaging the stimulated area, nullifying the effect of the prior art device.